In 1786 Menzies was appointed surgeon aboard Prince of Wales on a fur-trading voyage ‘round Cape Horn to the northern Pacific. This ship, in company of Princess Royal visited North America, China and Hawaii (the Sandwich Isles) several times. Menzies collected a number of new plants on this voyage, and ensured that none of the crew died of illness. Menzies returned to Great Britain in 1789 where he was elected a fellow of the Linnean Society, the world’s oldest botanical society.
In 1790, Menzies sailed as naturalist with Captain George Vancouver on his voyage around the world on HMS Discovery. When the ship’s surgeon fell ill, Menzies took over his duties.
Menzies’ name is commemorated in the scientific names of several of the plants he discovered including the Douglas-fir Pseudotsuga menziesii, the most commercially important tree in western North America. The arbutus, an evergreen tree, was named Arbutus menziesii in his honour by Friedrich Pursh.
In 1795, Menzies, while dining with the Viceroy of Chile, was served the seeds of the Chile Pine, Araucaria araucana, as dessert. He was able to pop a few seeds into his pocket and grow five healthy plants on the voyage home. Known as the Monkey Puzzle tree, the Chile Pine became a favourite in England’s 19th-century formal gardens.
Menzies then served with the Navy in the West Indies, received the degree of M.D. at the University of Aberdeen and, after his retirement from the Navy, practiced as a doctor and surgeon at Notting Hill, London. He became leader of the Linnean Society upon the death of A.B. Lambert. Menzies died in London on 15 February 1842 and is buried in Kensal Green cemetery.